Vacuum-pump.



A. MORAWSKI.

VACUUM PUMP.

APPLICATION FILED APILG, 1911.

1,049, 1 30, Patented Dec. 31, 1912.

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COLUMBIA PLANOGRAPH CO..WASHINGTON- 1L6v UTTE STATES PATENT QFFICALEKSANDER MORAWSKI, F WARSAW,.RUSSIA.

VACUUM-PUMP.

To all whom it may concern:

Be it known that I, ALEKSANDER MoRAw- SKI, a subject of the Czar ofRussia, and resident of lVarsaw, in the Empire of Russia, have inventedcertain new and useful Improvements in and Relating to Vacuum- Pumps, ofwhich the following is a specification.

This invention has for its object to furnish a new type of vacuum pumpin which use is made of an upright cylinder, which is partly filled withmercury or other sealing liquid, and closed at its upper end, and inwhich a piston is reciprocated by suitable mechanism, so that vacuumwork is done during its upward and downward stroke, while the sealingliquid, which is placed in the bottom of the cylinder, is distributed insuch a manner that all the sliding surfaces form a perfect joint, theoperation of the pump being such that an exhaust-air conduit passesthrough the cylinder to near the bottom thereof and is surrounded by adeliverypipe which is moved out of the mercury covering the bottom ofthe cylinder upon the production of a suction-effect beneath the piston,while at the commencement of the delivery-stroke it is immersed in theInercury, so that during the suction-stroke free access is afforded forthe exhaust-air, while during the delivery-stroke the air drawn in isprevented from passing back into the exhaust-air conduit and iscompelled to pass to the outside of the cylinder.

The principle of my improved vacuum pump, together with the details ofconstruction of the same, is illustrated in the accompanying drawings,in which Figure l is a vertical central section through the improvedvacuum pump, Fig. 2 is a plan-view of the cylinder-head, Fig. 3 is aplan of the intermediate cover below the cylinder-head, Fig. 4 is aplan-view of the bell-shaped piston, Fig. 5 is a detail vertical sectionthrough the cylinder-head and interior cover, Fig. 6 is a sectionalsideview of the guide-pipe for the clamping member of the centraldelivery-pipe of the cylinder, and Fig. 7 is a detail horizontalsection, on line 7, 7 Fig. 1, drawn on a larger scale, of thedriver-bolt for the delivery-pipe.

Similar reference characters indicate corresponding parts in thedifferent figures of the drawings.

The improved vacuum-pump consists of a base-frame l and a cylinder 2supported Specification of Letters Patent.

Application filed April 6, 1911.

Patented Dec. 31,1912. Serial No. 619,262.

thereon, on which cylinder the mechanism for operating the pump isarranged. This unechamsm consists of a crank-shaft 3 supported inbearings of the base-frame 1,

' cranks 4 on the shaft 3, and connecting rods 5 which impartreciprocating motion to a cross-head 6 which slides up and down on thestationary rods 7 attached to the exterior lugs at the upper end of thecylinder 2. In the cylinder is arranged a fixed bellshaped body 42,which forms the bottom of the cylinder, in such a manner that aninterval of some millimeters is left between the cylinder-wall 2 andbottom 42. In this interval a bell-shaped piston 43 is reciprocated, itsconical head 44 being formed with a cup-shaped enlargement 46 at theapex above the throat 45. Between this throat 45 and a central sealedsleeve 47 a small interval is left. A suction pipe 15 passes through thehead 17 and interior cover 16 into the pipe 47. The sealed sleeve 47surrounds the suction-pipe 15 which carries a delivery-valve 16. Thepipe 47 is formed at its upper end into a cup 48 which, as shown inFigs. 1 and 5, is connected with a clamplng member 27 on the head of thecylinder through the interior cover 16 and the head 17 of the cylinder.The clamping member 27 serves for intermittently raising or lowering thepipe 47 by its connection with the reciprocating cross-head 6, so thatthe lower end of the pipe 47 is alternately immersed into the mercury inthe cup 55 of the bellsha ed bottom 42 during the downward stro e of thepiston and lifted therefrom during the upward stroke.

The connection of the clamping member 27 with the cross-head 6 is madeby a driver bolt 25 (Figs. 2 and 7) which is resiliently mounted in thecross-head 6, its end being able to enter into a recess 26 in theclamping member 27. The clamping member 27 em braces asleeve 28connected with the pipe 15 which passes through the cover 17. As theclamping member 27 is adjustable in the head 17 of the cylinder in aguide-pipe 28, the interval between the lower end of the pipe' 15 andthe level of the mercury, and also the movement of the central sealedsleeve 47, can be regulated. In addition to embracing the pipe 28, theclamping member 27 also embraces a pipe 29 fixed on the head 17 in sucha manner that it is able to slide upon this pipe. At the commencement 1of the upward movement of the piston, the

driver-bolt 25 displaces the clamping member 27 until a fixed stop 30strikes against the conical head 31 of the bolt 25 and releases therebythe driver-bolt 25 from the clamping member 27. In the meantime,however, the clamping member 27 has come above the lower heel 32 of aspring-actuated lever 33 which is fulcrumed in the pipe 29, so that whenthe connection is disestablished the clamping member 27 is engaged bythe heel 32. In this manner the lower end of the sealed sleeve L7 ismaintained above the level of the mercury when the piston effects itsupward stroke. When the piston has reached its highest position, aroller 34 arranged on the cross-head strikes against a heel 35 at theupper end of the lever 33 in such a manner that the lower heel 32 ismoved inwardly into the pipe 29 and allows the clamping member 27 andthe sealed sleeve 47 to descend. In this manner when the piston movesdownward the sealed sleeve 47 is immersed in the mercury.

The bell-shaped piston 43 is provided at its upper part with a head 48in which two cylindrical bores with hardened bushes 4:9 are provided,and the piston-rods are screwed at the base of the cylindrical boresinto the head e8. To the inner cover 16 are attached two bush-likepistons 51, which correspond to the cylindrical bores in the head 48,and which pistons descend in the cylindrical bores in the intermediatecover 16. The bores in the cylinder 51 are closed at their upper ends byvalves 52 which are normally closed by helical springs 54 is a nipple,shown in Fig. 2, for the discharge of the exhaust-air, which is fittedto the cylinder 2 immediately below the cover 16.

The operation of the vacuum pump shown in Figs. 1 to 7 is as follows:The bottom of the pump-cylinder is filled with mercury in which thebell-shaped piston 4L3 moves up and down. In the lowest position of thepiston 4:3 the mercury flows over the upper face of the head 48* in sucha manner that the vessel 46, and also the cylindrical recesses in thehead e82 become filled with mercury. When the piston moves upward somemercury trickles from the vessel 46 between the throat 4:5 and thesealed sleeve 47, but the receptacle i6 is made of. such a size that inthe highest position of the piston the mercury is still able to overflowinto the cup L8 in such a manner that a good joint is formed by themercury in the space between the pipes 15 and sealed sleeve 47. When thepiston moves upward the sealed sleeve 47 is lifted out of the cup 55filled with mercury, while when the pis ton descends it is lowered intothe vessel. When the cylinder-pistons 51 enter the cylindrical bores inthe head 48 of the piston 43, the latter approaches the intermediatecover 16 and the mercury contained in the recesses is forced into thespace above the cover 16 in opposition to the spring-actuated valves 52and distributed by the passages 50 so as to form a good joint for thesliding surfaces. Nhile the exhaust-air is drawn into the space belowthe piston through the pipe 15, upon the ascent of the piston, and uponthe descent of the piston it is forced through the mercury in thecupshaped enlargement 46 into the space above the piston, as in thearrangement illustrated in Fig. 1 the air cannot be forced above theinterior cover 16. The air con ducted above the piston is drawn offthrough the nipple 5 L by an auxiliary pump of the kind which is usuallyemployed in vacuumpumps as heretofore constructed to render the mainpump C'fllClQllt in practice.

In the form of pump described, the selection of a suitable material isof the greatest importance. This material must be a nonoXidiZing metal,such as cobalt or nickel, and those parts which permanently contact withthe mercury and which are intended to form a joint therewith, must beformed of such a material that an ascending menicus results. Theseconditions are fulfilled by combinations or alloys of nickel, such asGerman silver or the like. It is therefore advisable that all partscoming into contact with the mercury should either be formed entirely ofGerman silver, or like nickel compounds, or of steel with a coating ofthese metals.

I claim:

1. In a vacuum piston-pump, the combination with an upright cylinder,containing mercury in the bottom-part thereof, and having a head, aninterior cover and an outmovable in the cylinder, piston-rods passingthrough the head and cover, a suction pipe passing through the head andcover and through the piston-head into the mercury, a central sealedsleeve surrounding the suction pipe, crank-driven means forreciproeating the piston, and means automatically controlled by thecrank-driven means for lifting the sealed sleeve from the mercury whenthe piston ascends and allowing it to return into the mercury in theuppermost position of the piston.

2. In a vacuum piston-pump, the combination with a vertical cylindercontaining mercury in the bottom-part thereof, and having a head, aninterior cover and an outlet, of a bell-shaped piston having aperforated head movable in the cylinder, pistonrods passing through thehead and cover, a suction pipe passing through the head and cover andthrough the piston-head into the mercury in the bottonrpart of thecylinder, a sealed sleeve surrounding the suction-pipe, spring-actuatedvalves in the piston-head, crank-driven means for reciproeating thepiston, and means automatically controlled by the crank-driven means forlifting the sealed sleeve from the mercury when the piston ascends andallowing the sealed sleeve to return into the mercury when the piston isin the upper position.

3. In a vacuum piston-pump, the combination with a vertical cylindercontaining mercury in the bottom-part thereof, and having a head, aninterior cover and an outlet, of a bell-shaped piston having aperforated head movable in the cylinder, piston-rods passing through thecylinder and cover, a suction-pipe passing through the head and coverand through the pistonhead into the lower part of the cylinder, a sealedsleeve surrounding the suction-pipe, a cross-head connected with thepiston-rods, a clamping member having connected with the sealed sleeve aspring-actuated driver-pin, a pin mounted in the cross-head and adaptedto engage a recess of the clamping member when the piston is ascendingand lift the sealed sleeve from the mercury, springactuated valves inthe piston-head, means mounted on the cylinder-head for engaging theclamping member and holding it above the level of the mercury while thepiston continues to rise, a member fixed on the cross-head for releasingsaid lifting means in the upper position of the piston, and means forreciprocating the cross-head.

4. In a vacuum pump, the combination with a vertical cylinder containingmercury in the bottom-part thereof and having a head, an interior coverand an outlet, of a pistonhaving a perforated head movable in thecylinder, piston-rods passing through the head and cover, an exhaustairpipe passing through the cover and cylinder-head, a sealed sleevesurrounding the exhaust-pipe and extending below the same into themercury in the bottom-part of the cylinder, said interior cover beingprovided with valves traversed by the piston-rods, crank-driven meansfor reciprocating the piston, and means automatically controlled by thecrankdriven means for lifting the scaled sleeve out of the mercury whenthe piston ascends and allowing said sleeve to return into the mercuryin the upper position of the piston.

5. In a vacuum piston-pump, the combi nation with a vertical cylindercontaining mercury in the bottom-part thereof and having a head, aninterior cover and an outlet, of a piston having a perforated headmovable in the cylinder, piston-rods passing through the head and cover,a suction pipe passing through the cover and through the piston-head, asealed sleeve surrounding the suction pipe and extending below the sameinto the mercury in the bottom-part of the cylinder, said interior coverbeing provided with valves traversed by the piston-rods, crank-drivenmeans for reciprocating the piston, means automatically controlled bysaid reciprocating means for lifting said sealed sleeve from the mercurywhen the piston ascends and allowing it to return in the upper positionof the piston, and means for lifting the mercury into the space abovethe interior cover for forming a good joint between the suction-pipe andsealed sleeve.

6. In a vacuum pump, the combination with a vertical cylinder having ahead, an interior cover, an outlet and a bottom in the form of a bellforming an annular space between the same and the side-wall of thecylinder and containing mercury in the annular space, of a pistoncomprising a bellshaped body movable in said annular space, a pluralityof piston-rods passing through the head and interior cover, asuction-pipe passing through the cylinder-head and cover into thecylinder, a sealed sleeve surrounding the suction-pipe and extendingfrom the piston-head into the upper part of the bottom, and means forreciprocating the piston.

7. In a vacuum-pump, the combination with a vertical cylinder having ahead, an interior cover and an outlet, a bottom in the form of a bellforming an annular space between the same and the sidewall of thecylinder and containing mercury in said annular space, a pistoncomprising a bell-shaped body movable in said annular space and aperforated head, a plurality of piston-rods passing through thecylinder-head and cover, a central suction pipe passing through thehead, cover and piston-head into the cylinder, a sealed sleevesurrounding the suction pipe and extending from the upper end of thebottom of the cylinder into the pistonhead, and means for reciprocatingthe piston, the piston-head having a plurality of cylindrical bores inthe upper face thereof and said interior cover a plurality of pistonsadapted to fit into said bores and force the mercury collected thereinin the lowermost position of the piston out of the same for forming amercury seal for the suction-pipe and sealed sleeve.

In testimony, that I claim the foregoing as my invention, I have signedmy name in presence of two subscribing witnesses.

ALEKSANDER MORAWSKI.

Witnesses:

FRANCIS TREMBIOKI, AUDREY KIRWAY.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

